An approach to dysmorphology for the fellowship paediatric examination (Australia) [email protected] Why bother – don’t we all just do an exome now? Detailed phenotyping improves the diagnostic yield of genomic testing • Why does exome sequencing not get an answer Technological Unknown gene-disease More complex genetics limitations associations (polygenic, epigenetic, Incomplete (noncoding or expansion mutations, multi-factorial,…. Non- incomplete coverage, uniparental recognition disomy, large indels, chromosomal genetic – yes it rearrangements, and copy-number variants) happens!!!!) of the patient’s Reanalysis of exome data win collaboration with referring physician can boost diagnosis by ~12% phenotype (Salmon et al. 2018) And it might just help you describe new genetic conditions for your patients! • RLIM is a candidate dosage sensitive gene for individuals with varying duplications of Xq13, intellectual disability and recognizable facial features Elizabeth E. Palmer,1,2,3,4,20* Renee Carroll,5,20 Marie Shaw,5 Raman Kumar,5 Andre E. Minoche,4 Melanie Leffler,1 Lucinda Murray,1 Rebecca Macintosh,3 Dale Wright,7,8 Chris Troedsen,9 Fiona McKenzie,10,11 Sharron Townshend,11 Michelle Ward,11 Urwah Nawaz,5 Anja Ravine,12 Cassandra K. Runke,13 Erik C. Thorland,13 Marybeth Hummel,14 Nicola Foulds,15 Olivier Pichon,16 Bertrand Isidor,16 Cédric Le Caignec,17 Ann Bye,2,3 Rani Sachdev,2,3 Edwin P. Kirk,2,3 Mark J. Cowley,18 Mike Field,1 and Jozef Gecz,5,19** 1 Genetics of Learning Disability Service, Waratah, NSW 2298, Australia. 2 School of Women’s and Children’s Health, UNSW Medicine, University of New South Wales, NSW 2031, Australia. 3 Sydney Children’s Hospital, Randwick, NSW 2031, Australia 4 Kinghorn Centre for Clinical Genomics, Garvan Institute, Darlinghurst, Sydney, NSW 2010, Australia 5 Adelaide Medical School and the Robinson Research Institute, University of Adelaide, Adelaide, SA5000, Australia6 St Vincent’s Clinical School, University of New South Wales, Sydney, Australia7 Discipline of Genomic Medicine and Discipline of Child & Adolescent Health, University of Sydney, Sydney, Australia8 Department of Cytogenetics, The Children’s Hospital at Westmead, Westmead, Australia 9 Children’s Hospital at Westmead, Sydney, Australia 10 School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia 11 Genetic Services of Western Australia, Perth, Western Australia, Australia12 Pathwest Laboratory Medicine WA, Perth, WA, Australia.13 Genomics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, USA 14 West Virginia University School of Medicine, Department of Pediatrics, Section of Medical Genetics Morgantown WV USA15 Wessex Clinical Genetics Services, Southampton, UK16 Service de génétique médicale - Unité de Génétique Clinique, CHU de Nantes - Hôtel Dieu, 44093 Nantes CEDEX 1, Franc 17 Service de génétique médicale, Institut fédératif de Biologie, CHU Hopital Purpan, 31059 Toulouse CEDEX 9, France 18 Children’s Cancer Institute, Lowy Cancer Research Centre, University of New South Wales, Randwick, New South Wales, Australia 199 Healthy Mothers, Babies and Children, South Australian Health and Medical Research 1 Institute, Adelaide, SA 5000, Australia. Dys (disordered) morph (shape, form) • Try and study and attempt to interpret patterns of human growth and structural defects • Malformation (an intrinsic developmental anomaly, e.g., spina bifida), • Disruption (an event disrupting intrinsically normal development, e.g., amniotic bands), • Deformation (an external force altering the shape of development, e.g., face shape due to severe oligohydramnios) and • Dysplasia (abnormal growth and maturation of cells, e.g., achondroplasia). • Syndrome ”a recognizable pattern of dysmorphic signs that have a common cause” Dysmorphology is just part of the puzzle • 3 generation pedigree • Look at the parents and sibs – ideally parent baby/child photos • What is the pattern of functional/ congenital anomalies • First line tests … [ now will be CMA and exome ] Terminology is important • We are all dysmorphic to some extent • Be gentle • ‘distinctive’ … • ‘ features that are unique to them/ not similar to the rest of the family’ Elements of Morphology: Standard Terminology for the …. Some good resources (ACMG series: Allanson et al….2009) An approach … with thanks to Noe A) General inspection A1) Growth • HC • Length/ Height • Weight • BMI • Centiles • Mid parental height Short and tall stature • Q? Proportionate or not proportionate. Compare to siblings. Pre or post natal onset • Short stature: non proportionate • Consider skeletal dysplasia MANY chromosomal and single gene neurodevelopmental genetic disorders affect growth Turner Silver Russell syndrome syndrome 1:2000 female IUGR (<<-2.SD_ poor growth after birth, a relatively large births head size, a triangular facial appearance, a prominent Complete or partial forehead (looking from the side of the face), body deletion of X asymmetry and significant feeding difficulties. Majority chromosome. have normal intelligence. Fertility impact Noonan 60% : detectable abnomality in imprinting regions chr 7 and 11 syndrome! Tall: Marfan, Homocystinuria, Klinefelters, Sotos • https://info.marfan.org/ • Diagnostic criteria • An FBN1 pathogenic variant known to be associated with Marfan syndrome AND one of the following: • Aortic root enlargement (Z-score ≥2.0) • Ectopia lentis • Demonstration of aortic root enlargement (Z- score ≥2.0) and ectopia lentis OR a defined combination of features throughout the body yielding a systemic score ≥7 Obesity: Prader-Willi, Bardet-Biedl Typical facial features; these are often subtle and are not • Hypotonia always present. Features include deeply set eyes, widely • Hypogonadism spaced eyes, downslanted palpebral fissures, a depressed nasal bridge, small mouth, malar flattening, and retrognathia. • Hyperphagia e. Brachydactyly and scars from excision of accessory digits f. Dental crowding • Cognitive impairment; difficult g. High palate behaviours h. Fundoscopy demonstrating rod-cone dystrophy Development, characteristic behaviours/autistic features • Rett syndrome – Clinical findings • Most distinguishing finding: A period of regression (range: ages 1-4 years) followed by recovery or stabilization (range: ages 2-10 years; mean: age 5 years) • Main findings • Partial or complete loss of acquired purposeful hand skills • Partial or complete loss of acquired spoken language or language skill (e.g., babble) • Gait abnormalities: impaired (dyspraxic) or absence of ability • Stereotypic hand movements including hand wringing/squeezing, clapping/tapping, mouthing, and washing/rubbing automatisms • Supportive findings • Breathing disturbances when awake • Bruxism when awake • Impaired sleep pattern • Abnormal muscle tone • Peripheral vasomotor disturbances • Scoliosis/kyphosis • Growth retardation • Small, cold hands and feet • Inappropriate laughing/screaming spells • Diminished response to pain Fragile X syndrome: autistic features – gaze • Intense eye communication - "eye pointing” avoidance very common, flapping hands, hyperactivity, Head Head circumference Shape Craniosynostosis - 0.5-3.4% Sagittal 50% (dolicocephlay) Coronal 22% (brachycephaly) Metopic 6% (trigonencephaly) Look at hands Fontanelles – Size and time of closure Radiology- sutures Thick/thin/hyperostosis Head: size, shape, fontanelles, sutures, hair Craniosynostosis syndromes (quality, quantity), position of hairline Face: shape, symmetry, forehead Alagille’s Low set ears Definition : Upper Ears insertion of the ear to the scalp below an • Size imaginary horizontal passing through the • Microtia/Anotia Macrotia inner canthi and • extend that line Shape posteriorly to the ear • Position • Configuration • Auricular tag • Pits • Creases • Hearing! Deafness: Goldenhar, CHARGE, Waardenburg, Treacher Collins, Alport, NF-2, BOR, GJB2 (connexin 26), Jervell and Lange Nielsen, Alport Fetal exposure to alcohol during the first trimester affects development of facial features. Nose A range of facial anomalies can occur as result of prenatal alcohol exposure. There are three features which commonly • size, occur across age, gender and ethnic groups: • shape, • Small palpebral fissures: short horizontal length of • nasal bridge, the eye opening, defined as the distance from the • tip, endocanthion to the • nostrils, exocanthion (points A and B on photo below) • philtrum • Smooth philtrum: diminished or absent ridges between the upper lip and nose • Thin upper lip: with small volume https://www.fasdhub.org.au/siteassets/pdfs/australian-guide-to- diagnosis-of-fasd_all-appendices.pdf Eyes Telecanthus – increased distance between inner canthus- varies with ethnicity Critically – is the intra- pupillary distance increased or not Hypertelorism- widely spaced eyes- increased intra- pupillary distance Mouth • mouth, Cleft lip/palate: 22q11 deletion, Stickler • jaw, • lips, Approx 50% of cleft lip/palate will have other anomalies isolated CP (30%) • teeth, isolated CL (11%) CLP (9%) • palate, Recurrence risk depends on family history and type: • tongue, Non syndromal cleft palate (CP) • One affected child RR 2% uvula, One affected parent RR 6% • midline One affected parent and one affected child RR 15% defects Non syndromal Cleft lip and palate One affected child RR 4% One affected parent RR 4% One affected parent and one affected child RR 10% Mandible • Agnathia • +/- holoprosencephaly • Micrognathia – • associated